Cocaine self-administration increases preprodynorphin, but not c-fos, mRNA in rat striatum

Neuroreport. 1993 May;4(5):543-6. doi: 10.1097/00001756-199305000-00020.


The impact of cocaine self-administration on the expression of striatal preprodynorphin and c-fos mRNA was examined with in situ hybridization histochemistry. Cocaine significantly increased preprodynorphin mRNA in the dorsal, but not ventral, striatum. Expression of c-fos mRNA in cocaine-administering rats did not differ from that in controls in all structures examined. These results indicate that the expression of preprodynorphin, but not c-fos, is upregulated in rat striatum as a consequence of cocaine self-administration. Furthermore, these data indicate that the regulation of preprodynorphin is dissociable from the expression of c-fos in rats exposed to repeated doses of cocaine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Cocaine / administration & dosage
  • Cocaine / pharmacology*
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism*
  • Dynorphins / biosynthesis*
  • Gene Expression / drug effects
  • Genes, fos*
  • In Situ Hybridization
  • Male
  • Neurons / drug effects
  • Neurons / metabolism
  • Nucleus Accumbens / drug effects
  • Nucleus Accumbens / metabolism
  • Protein Precursors / biosynthesis*
  • RNA, Messenger / biosynthesis*
  • Rats
  • Rats, Wistar
  • Reinforcement Schedule
  • Self Administration


  • Protein Precursors
  • RNA, Messenger
  • pre-prodynorphin
  • Dynorphins
  • Cocaine